Improved electrical properties and luminescence properties of lead-free KNN ceramics via phase transition

A new KNN-based lead-free luminescent ceramics, (1-x)(K0.48Na0.52)Nb0.96Sb0.04- x(Bi0.45Sm0.05Na0.5)ZrO3 (KNNS-xBSNZ, 0 ≤ x ≤ 0.05), was designed to further improve the properties, such as piezoelectricity, dielectricity, ferroelectricity, and fluorescence properties. It was found that the R–T phase boundary could be constructed when the ceramics with x = 0.03~0.04, and the two-phase coexistence endowed them with relatively superior properties (d33 = 260 pC/N, εr = 2185, TC = 250 oC, Pr = 21 µC/cm2, Ec = 15 kV/cm). Meanwhile, the KNNS-xBSNZ ceramics show good photoluminescence characteristics at room temperature, which can achieve the combination of the piezoelectric and luminescent properties. Hence, we believe that this work has important reference value for the popularization of the optoelectronic components and multifunctional applications.